Smoke generating apparatus



March 11, 1969 J. J. DICKMAN SMOKE GENERATING APPARATUS Sheet INVENTOR, JOHN J. 0/ CKMAN BY= Q;

Filed Jan. 9, 1967 ATTORNEY March 11, 1969 J. J. DICKMAN 3,432,439

SMOKE GENERATING APPARATUS Filed Jan. 9, 1967 Sheet 2 of IIIILLIII] 1 III] L] I VENTURI\ 5 23 LE 2 g SOURCE 24 E OF 5 PRESSURE 5 GAS z! 3| PREssuR GAS i LAMP SOLENOID HEATER VALVE K H I 8 2? FIG. 4

INV ENTOR JOHN J. DIG/(MAN em 62 W, KM

ATTORNEY United States Patent ABSTRACT OF THE DISCLOSURE An apparatus for producing smoke by subjecting a liquid fuel to an electrically heated resistance coil; there being means for delivering predetermined quantities of the liquid fuel to the coil under preselected pressure for controlling the characteristics of the emitted smoke.

6 Claims Background of the invention This invention relates to apparatus for generating smoke for visual detection purposes. Heretofore in the use of dioramas for military exercise purposes, there has been the need for causing a readily detectable, realistic signal to be presented upon the incidence of an explosionproducing event. Various types of electrical indicators have been used but not with the desired effectiveness. Thus, the present invention brings about the emission of a cloud of smoke at or near the point of the simulated explosion so as to lend a strong sense of reality to the exercise, as well as to provide the participants with an experience closely associated with that which might be encountered in an actual war zone. Furthermore, there has been difliculty heretofore in developing agents for effecting facile study of air flow in conduits of all types such as ducts, tunnels, vents and the like. With the present invention, a body of smoke may be cheaply and easily discharged into the path of air flow so as to allow viewers to watch the effects thereon and thereby gain a rapid insight as to the nature of the currents.

Summary of the invention It is an object of the present invention to provide apparatus for producing smoke for visible detection purposes such as, for instance, in air flow studies, in duct and vent systems, as well as in air tunnel experiments.

It is another object of the present invention to provide an apparatus of the character stated which can be effectively used in training devices, such as for military purposes for simulating explosions as in dioramas designed to represent battle areas.

It is a further object of the present invention to provide an apparatus of the character stated which may be most economically produced, having a marked simplicity of parts; which may be readily installed in operative position; may be utilized in multiple units; which isreliable and etficient in operation; and which may be easily installed in operative condition.

Brief description of the drawings FIGURE 1 is a perspective view of the smoke generating apparatus constructed in accordance with and embodying the present invention, illustrating same in operative position with respect to a terrain board for diorama purposes and with the main support bracket omitted.

FIGURE 2 is an elevational view, partly in section, of the smoke generating apparatus.

FIGURE 3 is an exploded perspective view of the smoke discharging unit and the associated elements.

FIGURE 4 is a circuit diagram of the electrical syslem of the smoke generating apparatus.

3,432,439 Patented Mar. 11, 1969 ICC Description of the preferred embodiment Referring now by reference characters to the drawings which illustrate the preferred embodiment of the present invention, A generally designates a smoke generating apparatus which, for purposes of illustration, is shown as used for diorama purposes being disposed on the underside of a terrain board or table 1, the upper surface of which may be suitably treated for simulatin a battle area. Board 1 is provided with an aperture 2 for each smoke generating apparatus A through which aperture the generated smoke will escape, as indicated at S in FIGURE 1, simulative of an explosion, as by a shell or the like, as more fully described hereinbelow. Apparatus A comprises a support structure which includes an angle bracket 3, having its horizontal flange 4 secured to the under face of board 1 as by screws 5 and with its other or vertical flange 6 depending downwardly; said latter flange being tapered in its lower margin, as at 6' and having a transversely extending arcuate slot 7 for receiving a pin 8 which is engaged to a vertically disposed support bar 9 which progresses downwardly with its lower end located spacedly below bracket 3. The upper end of *bar 9 is fixed to flange 6 of bracket 3 or the like 10. Thus, bar 9 may be disposed in any preselected vertically swung relation to bracket 3 by reason of slot 7 so as to allow for facile installation of apparatus A. Progressing upwardly from the lower end of bar 9 is an elongated longitudinally extending opening 11, the sides of which are designed to securely embrace bolts 12 extending through said opening 11 for securing same to the vertical wall 13 of a mounting bracket 14. Opening 11 accordingly permits of selected vertical disposition of'mounting bracket 14 with respect to support bar 9. Vertical wall 13 is provided with a cut-out as indicated at 15 for receivin a terminal plug 16. Mounting bracket 14 integrally incorporates a lower horizontal plate 17 which extends from the lower end of vertical wall 13 ina direction rearwardly, as viewed in FIGURE 2, for supported disposition thereon of a transformer 18. Also received upon plate 17 between transformer 18 and vertical wall 13 are the discharge conduits 19 of an atomizer, indicated generally at 20, and being disposed immediately laterally outwardly of the adjacent side edge of plate 17.

Atomizer 20 comprises a liquid receptacle 21 and a re movable cap 22, which latter carries a restricted fluid passage or venturi 23, the discharge end of which is suitably co-nnected by customary fittings to conduit 19; the inlet end of said latter being engaged, as by a fitting denoted 24, to a fluid supply tube 25. The throat of venturi 23 is connected to a tube 26 which extends downwardly within receptacle 21 for drawing the contents thereof upwardly into venturi 23 upon the development of reduced pressure therein as will be described more fully hereinbelow. Cap 22 is also provided with an aperture 27 for extension therethrough of a conduit 28 terminating at one end at a location preferably in alignment with the utilized for the purpose of recharging the receptacle with the smoke producing fluid.

Fluid supply tube 25 is engaged at its other end to a solenoid valve 29 suitably secured to the under surface of plate 17 and being connected by tubing 30 to a conveniently located source of pressure gas 31 which, if desired, may be air.

Vertical wall 13 of mounting bracket 14 on its side remote from that adjacent atomizer 20 is provided with a vertical flange 32 being suitably apertured (not shown) for engagement as by rivets, screws, or like attaching means, to a chimney 33 being of tubular form and being preferably formed of material adapted to resist deterioration through exposure to heat and also being preferably dielectric, such as from fibreglass-impregnated phenolics.

Chimney 33 is received at its upper end within the lower portion of table aperture 2 and at its lower end may terminate in substantial alignment with the bottom of atomizer receptacle 21 thereby conducive to the compactness of apparatus A. Flange 32 of mounting bracket 14 terminates above plate 17 for accommodating a fitting 34 which connects the nozzle forming ends of discharge conduits 19 as indicated at 35 to the inlet passage 36 of the glass housing 37 of a heating element indicated generally at H. Sai-d glass housing 37 is of general bulb form with inlet passage 36 projecting laterally from the upper side wall thereof through a suitable opening 38 in the side wall of chimney 33; said opening 38 extending to the bottom of chimney 33 so as to facilitate removal of elements H from, and installation of such elements in, chimney 33. Glass housing 37 is of such outside diameter as to be readily received within chimney 33'. Heating element H comprises a resistance coil 39 which is of spiral formation and disposed within housing 37. Coil 39 may be made of any suitable material, however, 22 gage Nichrome wire has been found to be a material of preference with the same being wound into a inch diameter coil. By reason of the relatively thick character of the selected wire, high durability is assured, as well as providing a relatively low resistance.

At its upper end glass housing 37 is provided with an upwardly projecting vertical extension 40 constituting an outlet passage. Extension 40 mounts a tubular sleeve 41, as of suitable lflexible material, which provides a continuation of extension 40; the upper end of said sleeve 41 terminating spacedly below the upper end of chimney 33.

There is also provided in the upper end of chimney 33 an incandescent lamp 42 engaged within a socket 43 carried upon a mounting clip 44 having outwardly biased arms 45, 45' for engaging the inner wall of chimney 33; said clip 44 carrying bosses 46, 46 for suitable connection by leads (not shown) to a source of electricity. Lamp 42 projects into aperture 2 and at its upper end is located slightly below the upper surface of board 1; there being a. mesh member 47 extending across aperture 2 so as to inhibit foreign particles from descending into chimney 33. With reference to FIGURE 2 it will be seen that sleeve 41 will be disposed in adjacency to lamp socket 43.

With reference to the wiring diagram being shown in FIGURE 4, it will be seen that heating element H is in circuit with transformer 18 whereby the latter may step down the voltage applied to said element H in view of its relatively low-resistance characteristics. For purposes of diorama usage, transformer 18 may be of such capacity so as to furnish 17% watts to heating element H which will be maintained in energized condition throughout the period of use of apparatus A. Transformer 18 may thus step down the customary line voltage of 115 volts to 12.6 volts for energizing purposes. But it is understood that the foregoing is merely exemplary since it is obvious that the electrical requirements will differ depending upon the application of the unit.

In operation, receptacle 21 of atomizer 20 will be supplied with a quantity of a liquid fuel, of non-toxic character, which is adapted at a predetermined temperature to be converted through combustion to smoke. Thus, upon provision of pressurized gas to atomizer 20, a predetermined quantity of the liquid fuel will be entrained by the vehicle-forming gas for transmission through discharge conduits 19, nozzle 35, and inlet 36 for subjection to the energized coil 39' within housing 37 whereby through combustion of the fuel, smoke will be emitted through extension 40 and sleeve 41 and thence outwardly through aperture 2 to create a visible mass, as shown at S in FIGURE 1. Although it does not form part of the present invention, apparatus A may be provided with a circuit for illumination of lamp 42 in timed relation to emission of smoke through aperture 2 so as to provide simulation of a flash thereby completing the illusion of an explosion.

From the foregoing it will thus be seen that by the circuitry provided, upon each actuation, solenoid valve 29 will operate for a predetermined time increment so as to allow a correlative quantity of pressurized gas to pass therethrough for carrying the liquid fuel to heater element H. The duration of operation of solenoid valve 29 may be easily predetermined with reference to the particular smoke characteristic sought, taking into account the pressure of the gas. It is recognized that such pressure may be preselected to achieve desired smoke flow. Thus, it has been found that gas pressure at 3 p.s.i. will cause the smoke to drift upwardly as from a slow burning fire, while at 60 p.s.i. the smoke will be rapidly dissipated. Gas at a pressure of 10 pounds per square inch has been found in practice to produce a very realistic smoke cloud having desired body and travel rate. The constituency of the liquid fuel may be a matter of choice and with the same determining the temperature of the heating element H in energized state so as to bring about the requisite combustion. For purposes of dioramas, as used for military instructional and educational purposes, a fuel having the following ingredients has been found highly effective, namely:

Parts Kerosene Methyl salicylate '20 Glycerine 1 Fuel so constituted will be converted to a smoke in a non-pyrotechnic manner at a temperature of approximately 400 F. so that element H will be maintained at such temperature during operation of apparatus A. The particular fuel utilized is not a part of the present invention but the foregoing will serve as an example of the type of preparation having properties desirable for use with the present invention.

From the foregoing the operation of apparatus A should be quite apparent; it being recognized that the same may be readily adapted for the particular conditions desired with appropriate selection of the pressure operating upon the gas vehicle; the interval of operation of solenoid valve 29 for permitting a preselected volume of gas to be delivered to atomizer 20, as well as choice of fuel and with commensurate temperature maintenance of element H.

FIGURE 4 demonstrates a simple wiring diagram for the system and with the same being connected to terminal plug 16 by appropriate leads for ultimate con nection to a convenient source of electricity. FIGURE 4 sets forth the circuit utilized in the smoke generating apparatus of the present invention.

FIGURE 1 shows a plurality of apparatuses A spacedly mounted upon the under surface of a terrain board 1 so as to bring about the emission of smoke clouds at various locations throughout the table surface which, as indicated above, is decorated to represent an embattled zone. It is apparent that a single remotely located control device could be used for causing discharge of smoke at selected points throughout terrain table 1 in accordance with the requirements and developments of a particular military exercise.

It will also be seen that apparatus A is extremely versatile in usage since the same provides an efiicient, reliable and easily operated system for providing visible smoke which can be used in airflow studies, such as in vents, ducts, air tunnels, and the like.

It should be understood that changes and modifications in the formation, construction, arrangement, and combination of the several parts of the smoke generating apparatus may be made and substituted for these herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to obtain by Letters Patent is:

1. An apparatus for generating smoke comprising a source of liquid fuel capable, upon combustion, of producing smoke, a source of a combustion supporting gas under preselected pressure, conduit means connecting said source of fuel and said source of gas, said connecting means comprising a venturi tube for entrainment of said liquid fuel via the venturi throat into said gas, a heating element, means defining a housing surrounding said heating element, said housing being of general glass bulb form having an inlet passage and an outlet passage, means for maintaining said heating element at a temperature for combustion of said gas and liquid fuel mixture, conduit forming means connected to said inlet passage for delivering the gas-carried fuel into direct contact with said heating element for smoke generation and then through said outlet passage.

2. An apparatus for generating smoke as defined in claim 1 and further characterized by the axis of said inlet passage being in normal relationship to the axis of said outlet passage.

3. An apparatus for generating smoke as defined in claim 1 and further characterized by chimney defining means surrounding said housing and progressing upwardly of said outlet passage thereof, said chimney being formed of dielectric material and having an opening in the sidewall thereof for receiving said conduit-forming means.

4. An apparatus for generating smoke as defined in claim 1 and further characterized by said outlet passage comprising an upwardly projecting vertical extension formed integral with said housing, said extension being of reduced diametrical dimension, the axis of said extension being normal to the axis of said inlet passage.

5. An apparatus as defined in claim 1 and further characterized by said heating element being of low re sistance wire and being spirally formed, said heating element being disposed in said housing in axially normal relationship to said inlet passage and in axially aligned relationship with said outlet passage.

6. In combination with a diorama terrain board having a plurality of apertures therein, a plurality of smoke generating apparatus mounted on the underface of said board adjacent each of said apertures, each said smoke generating apparatus comprising means defining a receptacle, a liquid fuel, capable upon combustion with a combustion supporting gas of producing smoke, contained with in said receptacle, a venturi mounted within said receptacle having two inlets and an outlet, tube means connecting the throat inlet of said venturi with said liquid fuel, a source of gas under preselected pressure, first conduit means connecting said source of gas with the other inlet of said venturi, a solenoid valve disposed in said first conduit means for controlling the volume of gas delivered to said venturi other inlet to entrain said fuel, a glass bulb having an inlet and an outlet, a spiral heating element provided within said bulb, means for heating said heating element to a predetermined temperature for combustion of said gas and liquid fuel mixture, second conduit means connecting the venturi outlet to said bulb inlet, said bulb outlet being in axially perpendicular relationship to the axis of said bulb inlet and in axially aligned relationship with the axis of said heating element, chimney defining means mounted within each of said apertures and depending downwardly from said terrain board, said glass bulb being adapted to be received within said chimney defining means, a lamp mounted within said chimney upwardly of said bulb outlet and proximate a said aperture and means for illuminating said lamp.

References Cited UNITED STATES PATENTS NORMAN YUDKOFF, Primary Examiner.

J. SOFER, Assistant Examiner.

U.S. Cl. X.R. 272-15 

